Personally I don't think this is significant. I think what you are seeing is the difference in white balance between the interior and the exterior. The cameras in the oval office have been set a certain way so that Biden's skin tone is correct, but the light coming from outside looks more blue/teal than it would if the cameras were outside and set to a daylight setting. Anyone who works in film knows that standard lights always need some CTB blue gels to mimic the color temperature of daylight.